@article{GDZPPN002045133,
title = {Extensions of countable infinitary logic which preserve most of its nice properties.},
journal = {Archiv f\"ur mathematische Logik und Grundlagenforschung},
volume = {20},
year = {1980},
pages = {95-102},
zbl = {0473.03031},
url = {http://dml.mathdoc.fr/item/GDZPPN002045133}
}
Harrington, Leo. Extensions of countable infinitary logic which preserve most of its nice properties.. Archiv für mathematische Logik und Grundlagenforschung, Tome 20 (1980) pp. 95-102. http://gdmltest.u-ga.fr/item/GDZPPN002045133/